Cryo-temperature monitoring

ABSTRACT

Devices and methods for cold-treating lesions within the body. A temperature monitoring device for use with a cryo therapy apparatus may include a cryo therapy apparatus, one or more tubular members coupled to the cryo therapy apparatus, and a temperature monitoring member coupled to the tubular member. The temperature monitoring member may comprise a retractable needle, an infrared sensor, an ultrasound transmitter, or a stent having a plurality of spikes.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention pertains generally to the field of cryotherapy. More particularly, the present invention pertains to cryoballoon therapy catheters for use in causing cold-induced necrosis.

[0003] 2. Description of the Related Art

[0004] A number of medical conditions may be treated using ablativetechniques or devices. Ablative techniques, generally, result in thenecrosis of abnormal tissue at an area of interest. Ablation of theabnormal tissue may result in an efficacious treatment for a medicalcondition. For example, atrial fibrillation may be the result ofabnormal electrical activity in the left atrium and the pulmonary vein,and may be treatable by ablation of the abnormal tissue within the leftatrium and/or the pulmonary vein.

[0005] Atrial fibrillation is a serious medical condition that is theresult of abnormal electrical activity within the heart. This abnormalactivity may occur at regions of the heart including the sino-atrial(SA) node, the atriovenricular (AV) node, the bundle of His, or withinother areas of cardiac tissue. Moreover, atrial fibrillation may becaused by abnormal activity within a isolated focal center within theheart. It is believed that these foci can originate within the pulmonaryvein, particularly the superior pulmonary veins.

[0006] Minimally invasive techniques have been described that useablation catheters to target the pulmonary vein with the hope ofablating foci having abnormal electrical activity. The techniquestypically are characterized by application of energy to cause lesionswithin the foci or other areas possessing abnormal electrical activity.

[0007] Some ablation devices utilize radio frequency (RF) energy forablation, including the device disclosed in U.S. Pat. No. 6,024,740 toLesh et al. The RF energy devices may be used to ablate an area ofinterest with heat. The use of RF energy for ablation may, however, leadto untoward healing responses such as collagen build up at the area ofinterest after treatment. Moreover, RF ablation of within an atrium maydecrease atrial output. A need, therefore, exists for ablative devicesand methods that include improved healing responses.

[0008] An alternative treatment strategy has been developed that usescooling energy for ablation. This method, termed cryoplasty or cryoballoon therapy, may be used to cool the lesion to freeze a portion ofthe affected area. For example, cryo balloon therapy may be used tofreeze a lesion within a blood vessel that might otherwise lead torestenosis or recoil.

[0009] In addition to its potential utility in preventing and slowingrestenosis and addressing recoil, cryo balloon therapy may be used forablation techniques. For example, cryo balloon therapy may beefficacious in varicose vein treatment of incompetent valves, valvulardisease, mitral valve regurgitation therapy, atrial fibrillation,gastric reflux disease, gastro esophageal reflux disease, GURD,esophageal disease, cancer treatment including stomach or uterinecancer, etc.

[0010] Uses of cryo balloon therapy include cold-induced necrosis ofcells within the body. When the target area is located within the heartor pulmonary vasculature, it may be important to precisely control thecryo balloon therapy catheter to necrosis only the desired tissue.Precise temperature regulation may be required to necrosis targettissues while minimizing damage to healthy tissue. Moreover, precisetemperature monitoring may be useful in target areas that have an unevensurface, such as trabeculae within the heart. A need, therefore, existsfor cryoplasty catheters with precise temperature monitoringcapabilities.

BRIEF SUMMARY OF THE INVENTION

[0011] The present invention pertains to a refinement to cryo therapycatheters that may incorporate some of the needs described above. Moreparticularly, the present invention comprises a temperature monitoringdevice for use with a cryo balloon therapy catheters. The temperaturemonitoring device may be coupled to a cryo therapy catheter and may beused to measure temperature while performing a medical procedure, forexample cryo balloon therapy or cryoplasty. The temperature monitoringdevice may comprise a tubular member having a temperature monitoringmember coupled thereto.

[0012] The temperature monitoring member may comprise a retractableneedle slidably disposed within a lumen of the tubular member.Alternatively, the temperature monitoring member comprises an infraredoptic sensor, an ultrasound transmitter, or a sheath that encircles thecryo therapy apparatus having a plurality of thermal spikes. Inaddition, one or more tubular members may be disposed about the cryotherapy apparatus in an array.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0013]FIG. 1 is a plan view of a cryo therapy apparatus including aretractable needle;

[0014]FIG. 2 is an alternate cryo therapy apparatus including aninfrared sensor;

[0015]FIG. 3 is a cross-sectional view of a quartet array arrangement oftubular members;

[0016]FIG. 4 is a cross-sectional view of an octet array arrangement oftubular members;

[0017]FIG. 5 is a second alternate embodiment of a cryo therapyapparatus including an ultrasound transmitter;

[0018]FIG. 6 is a detailed view of an arrangement of the tubular membersshown in FIG. 5;

[0019]FIG. 7 is a third alternate embodiment of a cryo therapy apparatusincluding a plurality of thermal spikes;

[0020]FIG. 8 is a fourth alternate embodiment of a cryo therapyapparatus.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The following description should be read with reference to thedrawings wherein like reference numerals indicate like elementsthroughout the several views. The detailed description and drawingsrepresent select embodiments and are not intended to be limiting.

[0022]FIG. 1 is a plan overview of a temperature monitoring device 10for use with a cryo therapy apparatus 12 according to an embodiment ofthe invention. Temperature monitoring device 10 may include a tubularmember 14 having a temperature monitoring member 20 coupled thereto.Temperature monitoring member 20 may be used to measure temperaturewhile performing a medical procedure, for example cryo therapy, cryoballoon therapy, or cryoplasty.

[0023] Tubular member 14 includes a proximal end 16 and a distal end 18.Tubular member 14 may be coupled to cryo therapy apparatus 12, forexample along the length or proximate an external surface of cryotherapy apparatus 12. Tubular member 14 may be comprised of materialsincluding, but not limited to, metals, stainless steel, nickel alloys,nickel-titanium alloys, thermoplastics, high performance engineeringresins, fluorinated ethylene propylene (FEP), polymer, polyethylene(PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane,polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK),polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene oxide(PPO), polysufone, nylon, perfluoro (propyl vinyl ether) (PFA),combinations thereof, or other suitable materials.

[0024] Cryo therapy apparatus 12 is substantially similar to analogousdevices (cryo therapy apparatuses, cryoplasty catheters, etc.) disclosedwithin U.S. Pat. No. 5,868,735 to Lafontaine and U.S. patent applicationSer. No. 09/849,892 to Lafontaine, the entire disclosures of which arehereby incorporated by reference. Briefly, cryo therapy apparatus 12 mayinclude a shaft with a cryoplasty device (e.g., a cryoplasty balloon)disposed at a distal end thereof. The shaft may include an inflationtube, a drain tube, and may further comprise an outer sheath defining anannular lumen between the outer sheath and the shaft. The annular lumenmay be sealed such that a vacuum may be maintained therein. Thecryoplasty device may include a single balloon or multiple balloons(i.e., a first balloon within a second balloon).

[0025] In use, coolant may pass through the inflation lumen into thecryoplasty device. The cryoplasty device may then be used for heattransfer with an area of interest. Coolant may be removed from thecryoplasty device through the drain tube following heat transfer.

[0026] Temperature monitoring member 20 may comprise a retractablethermocoupled needle 22 slidably disposed within a lumen 24 of tubularmember 14. According to this embodiment, the inside diameter of tubularmember 14 is sized appropriately for having temperature monitoringmember 20 disposed within lumen 24. Thermocoupled retractable needle 22is understood to include temperature sensing means that measuretemperature in a manner that is quantifiable by a clinician.Alternatively, retractable needle 22 may include a temperature sensorcoupled thereto. Retractable needle 22 may include a sharpened distalpoint 26 and at least one marker band 28. Distal point 26 may be adaptedto penetrate and/or cut into tissue during a medical procedure.

[0027] From FIG. 1 it can be appreciated that temperature monitoringmember 20 (and others described below) have a length along thelongitudinal axis and extends away from cryo therapy apparatus 12 alongthe longitudinal axis. Moreover, an angle may be defined betweentemperature monitoring member 20 and cryo therapy apparatus 12. Thisangle may be about 90°, acute, or obtuse. It can also be seen in FIG. 1that the length of temperature monitoring member 20 that extends fromcryo therapy apparatus is greater than its width (measured along theaxis perpendicular to the longitudinal axis).

[0028] Marker band 24 may produce a relatively bright image on afluoroscopy screen during a medical procedure. This relatively brightimage aids the user of marker band 24 in determining the location oftemperature monitoring member 20. Marker band 24 may comprise a numberof radiopaque materials including, but not limited to, gold, platinum,and plastic material loaded with a radiopaque filler. Temperaturemonitoring member 20 may further comprise additional marker bands or maycomprise a marker band disposed at a different location. For example,marker band 24 may comprise a first marker band (e.g., marker band 24) afixed distance from distal point 22 of temperature monitoring member 20.A second marker band may be disposed on temperature monitoring member 20proximally a distance that is approximately equal to the distance thefirst marker band is from distal point 22.

[0029] Proximal end 16 of tubular member 14 may be connected to amanifold 30. Manifold 30 comprises means for controlling temperaturemonitoring member 20. More specifically, manifold 30 may comprise meansfor quantifying temperature as measured by, for example, thermocoupledneedle 20. Means for quantifying temperature may include an analogtemperature reading or display, a digital temperature reading ordisplay, a connector for coupling to a computerized system for measuringtemperature, a computerized system for processing other data, andcombinations thereof.

[0030] In use, temperature monitoring device 10 may be advanced to anarea of interest. The area of interest may be, for example, an arteryincluding the pulmonary artery, a vein including the pulmonary vein, ablood vessel, the heart, trabeculae within the heart, a body organ, orother areas where cryoplasty may prove beneficial. Cryo therapyapparatus 12 may be used to cool the area of interest while temperaturemonitoring member 20 may be used to quantify temperature by insertingdistal point 26 into tissue at the area of interest. In an embodiment,distal point 26 may contact the surface of the tissue at the area ofinterest or it may penetrate and/or cut into the tissue to measuretemperature below the surface. Marker band 28 may be used to determinethe location of distal point 26 during heat transfer. Accuratelydetermining the location of distal point 26 may allow more precisecooling and prevent possible tissue damage due to over-cooling.Alternatively, the needles may have pre-determined depth markerband/stops which allow tissue penetration to a fixed depth such as 1-3mm, etc.

[0031]FIG. 2 is a plan view of an alternate temperature monitoringdevice 110 according to an embodiment of the invention. Temperaturemonitoring device 110 is substantially similar to temperature monitoringdevice 10 except that temperature monitoring member 120 comprises aninfrared or optic sensor 132. At least a portion of infrared or opticsensor 132 may be disposed within a lumen of tubular member 114, i.e.,the equivalent of lumen 24 of tubular member 14. Alternatively, infraredor optic sensor 132 may be disposed proximate distal end 218 of tubularmember 214.

[0032] Temperature monitoring device 110 may be used to measuretemperature at an area of interest by detecting infrared energy at thearea of interest with infrared sensor 32. Quantification of infraredenergy may comprise a measurement of heat and/or temperature. Manifold30 comprises means for quantifying temperature. For example, manifold 30may comprise means for quantifying infrared energy.

[0033] Cooling may result in the formation of ice or ice balls adjacentcryo therapy apparatus 12 and/or the treatment site. As a result,alternative temperature monitoring members may be used. For example, inorder to monitor or otherwise visualize ice or ice ball formation,optical sensing may be used. Optic sensing may be looking at the iceball visually by color change or appearance of ice. Other methods may beused as described herein to monitor ice formation as well as methodsknown to those in the art.

[0034]FIG. 3 and FIG. 4 depict a plan overview of arrangements oftubular members 14 taken through section 3/4-3/4 of FIG. 1 and depictingadditional tubular members 14. More than one tubular member 14 may bedisposed about cryo therapy apparatus 12 in an array. Four tubularmembers 14 may be disposed about cryo therapy apparatus 12 in a quartetarray as shown in FIG. 3. Similarly, FIG. 4 depicts eight tubularmembers 14, evenly spaced between, and disposed about cryo therapyapparatus 12 in an octet array. Although FIG. 3 and FIG. 4 depictarrangements of tubular member 14, it should be understood that any ofthe tubular members, temperature monitoring devices, and analogousstructures disclosed herein may be substituted without departing fromthe spirit of the invention.

[0035]FIG. 5 is a plan view of an alternate temperature monitoringdevice 210 according to an embodiment of the invention. Temperaturemonitoring device 210 is substantially similar to temperature monitoringdevice 10 except that temperature monitoring member 220 comprises anultrasound transmitter 234. Similar to what is disclosed above, at leasta portion of ultrasound transmitter 234 may be disposed within a lumenof tubular member 214 or ultrasound transmitter 234 may be disposed atdistal end 218 of tubular member 214.

[0036] Temperature monitoring device 210 may be used to measuretemperature at an area of interest by transmitting ultrasound energyfrom ultrasound transmitter 234. Manifold 30 may comprise means forquantifying temperature including means for accumulating ultrasoundimages, ultrasound energy, and other ultrasound data. Analysis ofultrasound images, ultrasound energy, and other ultrasound data mayprovide an indirect measurement of temperature. For example, anultrasound image may be used to view a phase change within the area ofinterest. The phase change may indicate a quantifiable level of cooling.

[0037]FIG. 6 is a detailed view of a tubular members 214 taken throughline 6-6 of FIG. 5 and depicting addition tubular members 214. In anembodiment, tubular members 214 may be disposed about cryo therapyapparatus 12 in an array. In an exemplary embodiment, the array may be acircular array. The circular array may enable a user to more preciselymeasure temperature and determine the location of temperature monitoringdevice 210. In addition, tubular members 214 may be arranged in aquartet or octet array as disclosed above, and tubular members 14 and114 may also be arranged in a circular array.

[0038]FIG. 7 is a plan view of an alternate temperature monitoringdevice 310 according to an embodiment of the invention. Temperaturemonitoring device 310 is substantially similar to temperature monitoringdevice 10 with a number of refinements described below.

[0039] Tubular member 314 comprises a sheath that, encircles cryotherapy apparatus 12. Temperature monitoring member 320 comprises astent 36 disposed at distal end 318 of tubular member 314. Stent 36 mayfurther comprise a plurality of thermal spikes 38. Stent 36 is comprisedof a shape memory alloy (e.g., nickel-titanium alloy). Alternatively,stent 36 may be comprised of materials similar to those listed aboveincluding metals and polymers.

[0040] Thermal spikes 38 may be capable of measuring temperature at anarea of interest. According to this embodiment, thermal spikes 38 may becoupled to manifold 30 such that a user may quantify temperature.Manifold 30 may comprise means for quantifying temperature includingthose listed above.

[0041] In addition, thermal spikes 38 may be used to facilitate heattransfer to an area of interest. For example, trabeculae within theheart may not allow cryo therapy apparatus 12 to evenly cool the heart.The result may be uneven or incomplete heat transfer. Thermal spikes 38may be capable of reaching, contacting, and penetrating surfaces of anarea of interest. For example, thermal spikes 38 may be capable ofcontacting trabeculae within the heart and may, thus, facilitate heattransfer to these areas.

[0042] In an embodiment, stent 36 may be collapsed at body temperatureand be expanded when cooled. A collapsed state at body temperature willminimize the outside diameter of stent 36, which may facilitate deliveryof temperature monitoring device 310 to an area of interest. Cooling,for example cooling initiated by cryo therapy apparatus 12, may expandstent 36 in order to move thermal spikes 38 proximate the area ofinterest.

[0043]FIG. 8 illustrates another alternative temperature monitoringdevice 410. Device 410 includes cryo therapy apparatus 412 coupled tomanifold 30 essentially as described above. In addition, tubular member414 may be coupled to cryo therapy apparatus 412. For example, tubularmember 414 may be disposed at least partially within cryo therapyapparatus 12 or within the shaft portion of cryo therapy apparatus 12.When disposed within cryo therapy apparatus 12, tubular member 414 maybe substantially coaxial with or proximate an interior wall of apparatus12.

[0044] Temperature monitoring member 420 may be disposed within tubularmember 441 and may extend into cryo therapy apparatus 12. In analternative embodiment, temperature monitoring member 420 may bedisposed within cryo therapy apparatus 12 without the use of tubularmember 441. For example, temperature monitoring member 420 may bedisposed within the shaft of cryo therapy apparatus 12.

[0045] Temperature monitoring member 420 includes an optical imagingapparatus 434 including an emitter 440 and a detector 442. Emitter 440is adapted and configured to emit energy (e.g., light, infrared energy,ultrasonic energy, etc.) from within cryo therapy apparatus. Detector442 is adapted to collect data by detecting energy. A number ofdifferent arrangements of emitters and/or detectors may be used withoutdeparting from the spirit of the invention.

[0046] Cryo therapy apparatus 412 is essentially the same in form andfunction as cryo therapy apparatus 12 but further includes an innercooling chamber 444 and an outer cooling chamber 446. A dual-chambercooling apparatus (such as apparatus 412) may provide additional safetyor cooling advantages. For example, outer cooling chamber 446 mayprevent loss of coolant into the body if inner cooling chamber 444failed. It can be appreciated that the dual chamber cooling apparatus412 can be substituted into any of the other embodiments describedherein.

[0047] Numerous advantages of the invention covered by this documenthave been set forth in the foregoing description. It will be understood,however, that this disclosure is, in many respects, only illustrative.Changes may be made in details, particularly in matters of shape, size,and arrangement of steps without exceeding the scope of the invention.The invention's scope is, of course, defined in the language in whichthe appended claims are expressed.

What is claimed is:
 1. A temperature monitoring device for use with acryo therapy apparatus, comprising: a cryo therapy apparatus; a tubularmember coupled to the cryo therapy apparatus; and a temperaturemonitoring member coupled to the tubular member.
 2. The temperaturemonitoring device according to claim 1, wherein the temperaturemonitoring member is coupled to the cryo therapy apparatus in a quartetarray.
 3. The temperature monitoring device according to claim 1,wherein the temperature monitoring member is coupled to the cryo therapyapparatus in a octet array.
 4. The temperature monitoring deviceaccording to claim 1, wherein the temperature monitoring member iscoupled to the cryo therapy apparatus in a circular array.
 5. Thetemperature monitoring device according to claim 1, wherein the tubularmember further comprises a proximal end, a distal end, and a lumenextending therethrough.
 6. The temperature monitoring device accordingto claim 5, wherein the temperature monitoring member comprises aretractable needle slidably disposed within the lumen of the tubularmember.
 7. The temperature monitoring device according to claim 6,wherein the retractable needle further comprises a marker band.
 8. Thetemperature monitoring device according to claim 1, wherein thetemperature monitoring member comprises an infrared sensor.
 9. Thetemperature monitoring device according to claim 1, wherein thetemperature monitoring member comprises an ultrasound transmitter. 10.The temperature monitoring device according to claim 1, wherein thetemperature monitoring member comprises an expandable stent having aplurality of thermal spikes.
 11. The temperature monitoring deviceaccording to claim 11, wherein the stent comprises nickel-titaniumalloy.
 12. A temperature monitoring device for use with a cryo therapyapparatus, comprising: a cryo therapy apparatus; a plurality of tubularmembers coupled to the cryo therapy apparatus, the tubular members eachcoupled to a temperature monitoring member and arranged in an array; andwherein the temperature monitoring member can measure the temperature atan area of interest while the cryoplasty device cools the area ofinterest.
 13. The temperature monitoring device according to claim 12,wherein the tubular member further comprises a proximal end, a distalend, and a lumen extending therethrough.
 14. The temperature monitoringdevice according to claim 13, wherein the temperature monitoring membercomprises a retractable needle slidably disposed within the lumen of thetubular member.
 15. The temperature monitoring device according to claim14, wherein the retractable needle further comprises a marker band. 16.The temperature monitoring device according to claim 12, wherein thetemperature monitoring member comprises an infrared sensor.
 17. Thetemperature monitoring device according to claim 12, wherein thetemperature monitoring member comprises an ultrasound transmitter. 18.The temperature monitoring device according to claim 12, wherein thetemperature monitoring members are arranged in a quartet array.
 19. Thetemperature monitoring device according to claim 12, wherein thetemperature monitoring members are arranged in an octet array.
 20. Thetemperature monitoring device according to claim 12, wherein thetemperature monitoring members are arranged in a circular array.
 21. Thetemperature monitoring device according to claim 12, wherein thetemperature monitoring member an expandable stent having a plurality ofthermal spikes.
 22. The temperature monitoring device according to claim21, wherein the stent comprises nickel-titanium alloy.
 23. A method ofmonitoring the temperature of an area of interest during a cryoplastyprocedure, comprising the steps of: providing a temperature monitoringdevice including a cryo therapy apparatus, a tubular member coupled tothe cryo therapy apparatus, the tubular member including a temperaturemonitoring member; advancing the temperature monitoring device to anarea of interest; cooling the area of interest with the cryo therapyapparatus; and measuring temperature at the area of interest with thetemperature monitoring member.
 24. The method according to claim 23,wherein the tubular member further comprises a proximal end, a distalend, and a lumen extending therethrough.
 25. The method according toclaim 24, wherein the temperature monitoring member comprises aretractable needle slidably disposed within the lumen of tubular member.26. The method according to claim 25, wherein the retractable needlefurther comprises a marker band.
 27. The method according to claim 26,wherein the step of measuring temperature with the temperaturemonitoring member includes penetrating the area of interest with theretractable needle.
 28. The method according to claim 23, wherein thetemperature monitoring member comprises an infrared sensor.
 29. Themethod according to claim 28, wherein the step of measuring temperaturewith the temperature monitoring member includes detecting infraredenergy at the area of interest.
 30. The method according to claim 23,wherein the temperature monitoring member comprises an ultrasoundtransmitter.
 31. The method according to claim 30, wherein the step ofmeasuring temperature with the temperature monitoring member includesirradiating the area of interest with ultrasound energy.
 32. The methodaccording to claim 23, wherein the temperature monitoring member anexpandable stent having a plurality of thermal spikes.
 33. The methodaccording to claim 32, wherein the step of measuring temperature withthe temperature monitoring member includes penetrating the area ofinterest with the thermal spike.
 34. The method according to claim 32,wherein the stent comprises nickel-titanium alloy.
 35. A temperaturemonitoring device for use with a cryo therapy apparatus, comprising: acryo therapy apparatus; a tubular member coupled to the cryo therapyapparatus; and a temperature monitoring member coupled to the tubularmember, the temperature monitoring member having a length extending fromthe cryo therapy apparatus along a longitudinal axis and a width; andwherein the length of the temperature monitoring member extending awayfrom the cryo therapy apparatus along the longitudinal axis is largerthan the width.
 36. The temperature monitoring device in accordance withclaim 35, wherein the temperature monitoring member extends from thecryo therapy apparatus at an angle.
 37. The temperature monitoringdevice in accordance with claim 36, wherein the angle is about 90°. 38.The temperature monitoring device in accordance with claim 36, whereinthe angle is acute.
 39. The temperature monitoring device in accordancewith claim 36, wherein the angle is obtuse.
 40. A temperature monitoringdevice for use with a cryo therapy apparatus, comprising: a cryo therapyapparatus; and a temperature monitoring member coupled to the cryotherapy apparatus, wherein at least a portion of the temperaturemonitoring member is disposed within the cryo therapy apparatus.
 41. Atemperature monitoring device for use with a cryo therapy apparatus,comprising: an elongate shaft having a distal end; a cooling chamberdisposed that the distal end of the shaft; a temperature monitoringmember coupled to the shaft, wherein at least a portion of thetemperature monitoring member is disposed within the cooling chamber.42. The temperature monitoring device in accordance with claim 41,wherein the cooling chamber includes an outer cooling chamber and aninner cooling chamber.